Patent application FR-93/07,077 filed by the applicant describes a transfer system for taking in balancing cells samples kept at high pressures analogous to those prevailing in subsoil formations where they have been initially taken. This system includes a sampling cell withstanding pressures higher than 100 MPa and temperatures of several hundred degrees above or below 0.degree. C., suited for sampling small amounts (of the order of several cm.sup.3) of fluid samples under pressure. The fluids contained in the sampling cell are transferred into measuring devices in order to be measured and analyzed. The fluid may for example be expanded with a change in the temperature thereof, so as to measure under standard pressure and temperature conditions the proportion of liquid and gaseous volume. To that effect notably, the two phases have to be separated properly.
A separating device generally includes a vessel with a lateral inlet for the injection of a two-phase mixture, placed above the level likely to be reached by the liquid phase and a separation space. The gas phase flows out through an upper port whereas the liquid phase is collected at the base of the vessel.
It is known to offset the lateral inlet port with respect to the axis of the flask so as to obtain a cyclone effect and a centrifugal force which drives the liquid phase of the sample away from the upper port, which facilitates the separation of the phases of the injected fluid.
Such a separating device is for example described in U.S. Pat. No. 4,713,095.